view tests/test-hgweb.t @ 26623:5a95fe44121d

clonebundles: support for seeding clones from pre-generated bundles

Cloning can be an expensive operation for servers because the server
generates a bundle from existing repository data at request time. For
a large repository like mozilla-central, this consumes 4+ minutes
of CPU time on the server. It also results in significant network
utilization. Multiplied by hundreds or even thousands of clients and
the ensuing load can result in difficulties scaling the Mercurial server.

Despite generation of bundles being deterministic until the next
changeset is added, the generation of bundles to service a clone request
is not cached. Each clone thus performs redundant work. This is
wasteful.

This patch introduces the "clonebundles" extension and related
client-side functionality to help alleviate this deficiency. The
client-side feature is behind an experimental flag and is not enabled by
default.

It works as follows:

1) Server operator generates a bundle and makes it available on a
   server (likely HTTP).
2) Server operator defines the URL of a bundle file in a
   .hg/clonebundles.manifest file.
3) Client `hg clone`ing sees the server is advertising bundle URLs.
4) Client fetches and applies the advertised bundle.
5) Client performs equivalent of `hg pull` to fetch changes made since
   the bundle was created.

Essentially, the server performs the expensive work of generating a
bundle once and all subsequent clones fetch a static file from
somewhere. Scaling static file serving is a much more manageable
problem than scaling a Python application like Mercurial. Assuming your
repository grows less than 1% per day, the end result is 99+% of CPU
and network load from clones is eliminated, allowing Mercurial servers
to scale more easily. Serving static files also means data can be
transferred to clients as fast as they can consume it, rather than as
fast as servers can generate it. This makes clones faster.

Mozilla has implemented similar functionality of this patch on
hg.mozilla.org using a custom extension. We are hosting bundle files in
Amazon S3 and CloudFront (a CDN) and have successfully offloaded
>1 TB/day in data transfer from hg.mozilla.org, freeing up significant
bandwidth and CPU resources. The positive impact has been stellar and
I believe it has proved its value to be included in Mercurial core. I
feel it is important for the client-side support to be enabled in core
by default because it means that clients will get faster, more reliable
clones and will enable server operators to reduce load without
requiring any client-side configuration changes (assuming clients are
up to date, of course).

The scope of this feature is narrowly and specifically tailored to
cloning, despite "serve pulls from pre-generated bundles" being a valid
and useful feature. I would eventually like for Mercurial servers to
support transferring *all* repository data via statically hosted files.
You could imagine a server that siphons all pushed data to bundle files
and instructs clients to apply a stream of bundles to reconstruct all
repository data. This feature, while useful and powerful, is
significantly more work to implement because it requires the server
component have awareness of discovery and a mapping of which changesets
are in which files. Full, clone bundles, by contrast, are much simpler.

The wire protocol command is named "clonebundles" instead of something
more generic like "staticbundles" to leave the door open for a new, more
powerful and more generic server-side component with minimal backwards
compatibility implications. The name "bundleclone" is used by Mozilla's
extension and would cause problems since there are subtle differences
in Mozilla's extension.

Mozilla's experience with this idea has taught us that some form of
"content negotiation" is required. Not all clients will support all
bundle formats or even URLs (advanced TLS requirements, etc). To ensure
the highest uptake possible, a server needs to advertise multiple
versions of bundles and clients need to be able to choose the most
appropriate from that list one. The "attributes" in each
server-advertised entry facilitate this filtering and sorting. Their
use will become apparent in subsequent patches.

Initial inspiration and credit for the idea of cloning from static files
belongs to Augie Fackler and his "lookaside clone" extension proof of
concept.

#require serve

Some tests for hgweb. Tests static files, plain files and different 404's.

  $ hg init test
  $ cd test
  $ mkdir da
  $ echo foo > da/foo
  $ echo foo > foo
  $ hg ci -Ambase
  adding da/foo
  adding foo
  $ hg bookmark -r0 '@'
  $ hg bookmark -r0 'a b c'
  $ hg bookmark -r0 'd/e/f'
  $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
  $ cat hg.pid >> $DAEMON_PIDS

manifest

  $ (get-with-headers.py localhost:$HGPORT 'file/tip/?style=raw')
  200 Script output follows
  
  
  drwxr-xr-x da
  -rw-r--r-- 4 foo
  
  
  $ (get-with-headers.py localhost:$HGPORT 'file/tip/da?style=raw')
  200 Script output follows
  
  
  -rw-r--r-- 4 foo
  
  

plain file

  $ get-with-headers.py localhost:$HGPORT 'file/tip/foo?style=raw'
  200 Script output follows
  
  foo

should give a 404 - static file that does not exist

  $ get-with-headers.py localhost:$HGPORT 'static/bogus'
  404 Not Found
  
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
  <head>
  <link rel="icon" href="/static/hgicon.png" type="image/png" />
  <meta name="robots" content="index, nofollow" />
  <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
  <script type="text/javascript" src="/static/mercurial.js"></script>
  
  <title>test: error</title>
  </head>
  <body>
  
  <div class="container">
  <div class="menu">
  <div class="logo">
  <a href="https://mercurial-scm.org/">
  <img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial" /></a>
  </div>
  <ul>
  <li><a href="/shortlog">log</a></li>
  <li><a href="/graph">graph</a></li>
  <li><a href="/tags">tags</a></li>
  <li><a href="/bookmarks">bookmarks</a></li>
  <li><a href="/branches">branches</a></li>
  </ul>
  <ul>
  <li><a href="/help">help</a></li>
  </ul>
  </div>
  
  <div class="main">
  
  <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
  <h3>error</h3>
  
  <form class="search" action="/log">
  
  <p><input name="rev" id="search1" type="text" size="30"></p>
  <div id="hint">Find changesets by keywords (author, files, the commit message), revision
  number or hash, or <a href="/help/revsets">revset expression</a>.</div>
  </form>
  
  <div class="description">
  <p>
  An error occurred while processing your request:
  </p>
  <p>
  Not Found
  </p>
  </div>
  </div>
  </div>
  
  <script type="text/javascript">process_dates()</script>
  
  
  </body>
  </html>
  
  [1]

should give a 404 - bad revision

  $ get-with-headers.py localhost:$HGPORT 'file/spam/foo?style=raw'
  404 Not Found
  
  
  error: revision not found: spam
  [1]

should give a 400 - bad command

  $ get-with-headers.py localhost:$HGPORT 'file/tip/foo?cmd=spam&style=raw'
  400* (glob)
  
  
  error: no such method: spam
  [1]

  $ get-with-headers.py --headeronly localhost:$HGPORT '?cmd=spam'
  400 no such method: spam
  [1]

should give a 400 - bad command as a part of url path (issue4071)

  $ get-with-headers.py --headeronly localhost:$HGPORT 'spam'
  400 no such method: spam
  [1]

  $ get-with-headers.py --headeronly localhost:$HGPORT 'raw-spam'
  400 no such method: spam
  [1]

  $ get-with-headers.py --headeronly localhost:$HGPORT 'spam/tip/foo'
  400 no such method: spam
  [1]

should give a 404 - file does not exist

  $ get-with-headers.py localhost:$HGPORT 'file/tip/bork?style=raw'
  404 Not Found
  
  
  error: bork@2ef0ac749a14: not found in manifest
  [1]
  $ get-with-headers.py localhost:$HGPORT 'file/tip/bork'
  404 Not Found
  
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
  <head>
  <link rel="icon" href="/static/hgicon.png" type="image/png" />
  <meta name="robots" content="index, nofollow" />
  <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
  <script type="text/javascript" src="/static/mercurial.js"></script>
  
  <title>test: error</title>
  </head>
  <body>
  
  <div class="container">
  <div class="menu">
  <div class="logo">
  <a href="https://mercurial-scm.org/">
  <img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial" /></a>
  </div>
  <ul>
  <li><a href="/shortlog">log</a></li>
  <li><a href="/graph">graph</a></li>
  <li><a href="/tags">tags</a></li>
  <li><a href="/bookmarks">bookmarks</a></li>
  <li><a href="/branches">branches</a></li>
  </ul>
  <ul>
  <li><a href="/help">help</a></li>
  </ul>
  </div>
  
  <div class="main">
  
  <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
  <h3>error</h3>
  
  <form class="search" action="/log">
  
  <p><input name="rev" id="search1" type="text" size="30"></p>
  <div id="hint">Find changesets by keywords (author, files, the commit message), revision
  number or hash, or <a href="/help/revsets">revset expression</a>.</div>
  </form>
  
  <div class="description">
  <p>
  An error occurred while processing your request:
  </p>
  <p>
  bork@2ef0ac749a14: not found in manifest
  </p>
  </div>
  </div>
  </div>
  
  <script type="text/javascript">process_dates()</script>
  
  
  </body>
  </html>
  
  [1]
  $ get-with-headers.py localhost:$HGPORT 'diff/tip/bork?style=raw'
  404 Not Found
  
  
  error: bork@2ef0ac749a14: not found in manifest
  [1]

try bad style

  $ (get-with-headers.py localhost:$HGPORT 'file/tip/?style=foobar')
  200 Script output follows
  
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
  <head>
  <link rel="icon" href="/static/hgicon.png" type="image/png" />
  <meta name="robots" content="index, nofollow" />
  <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
  <script type="text/javascript" src="/static/mercurial.js"></script>
  
  <title>test: 2ef0ac749a14 /</title>
  </head>
  <body>
  
  <div class="container">
  <div class="menu">
  <div class="logo">
  <a href="https://mercurial-scm.org/">
  <img src="/static/hglogo.png" alt="mercurial" /></a>
  </div>
  <ul>
  <li><a href="/shortlog/tip">log</a></li>
  <li><a href="/graph/tip">graph</a></li>
  <li><a href="/tags">tags</a></li>
  <li><a href="/bookmarks">bookmarks</a></li>
  <li><a href="/branches">branches</a></li>
  </ul>
  <ul>
  <li><a href="/rev/tip">changeset</a></li>
  <li class="active">browse</li>
  </ul>
  <ul>
  
  </ul>
  <ul>
   <li><a href="/help">help</a></li>
  </ul>
  </div>
  
  <div class="main">
  <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
  <h3>
   directory / @ 0:<a href="/rev/2ef0ac749a14">2ef0ac749a14</a>
   <span class="tag">tip</span> <span class="tag">@</span> <span class="tag">a b c</span> <span class="tag">d/e/f</span> 
  </h3>
  
  <form class="search" action="/log">
  
  <p><input name="rev" id="search1" type="text" size="30" /></p>
  <div id="hint">Find changesets by keywords (author, files, the commit message), revision
  number or hash, or <a href="/help/revsets">revset expression</a>.</div>
  </form>
  
  <table class="bigtable">
  <thead>
  <tr>
    <th class="name">name</th>
    <th class="size">size</th>
    <th class="permissions">permissions</th>
  </tr>
  </thead>
  <tbody class="stripes2">
  <tr class="fileline">
    <td class="name"><a href="/file/tip/">[up]</a></td>
    <td class="size"></td>
    <td class="permissions">drwxr-xr-x</td>
  </tr>
  
  <tr class="fileline">
  <td class="name">
  <a href="/file/tip/da">
  <img src="/static/coal-folder.png" alt="dir."/> da/
  </a>
  <a href="/file/tip/da/">
  
  </a>
  </td>
  <td class="size"></td>
  <td class="permissions">drwxr-xr-x</td>
  </tr>
  
  <tr class="fileline">
  <td class="filename">
  <a href="/file/tip/foo">
  <img src="/static/coal-file.png" alt="file"/> foo
  </a>
  </td>
  <td class="size">4</td>
  <td class="permissions">-rw-r--r--</td>
  </tr>
  </tbody>
  </table>
  </div>
  </div>
  <script type="text/javascript">process_dates()</script>
  
  
  </body>
  </html>
  

stop and restart

  $ killdaemons.py
  $ hg serve -p $HGPORT -d --pid-file=hg.pid -A access.log
  $ cat hg.pid >> $DAEMON_PIDS

Test the access/error files are opened in append mode

  $ $PYTHON -c "print len(file('access.log').readlines()), 'log lines written'"
  14 log lines written

static file

  $ get-with-headers.py --twice localhost:$HGPORT 'static/style-gitweb.css' - date etag server
  200 Script output follows
  content-length: 6412
  content-type: text/css
  
  body { font-family: sans-serif; font-size: 12px; border:solid #d9d8d1; border-width:1px; margin:10px; background: white; color: black; }
  a { color:#0000cc; }
  a:hover, a:visited, a:active { color:#880000; }
  div.page_header { height:25px; padding:8px; font-size:18px; font-weight:bold; background-color:#d9d8d1; }
  div.page_header a:visited { color:#0000cc; }
  div.page_header a:hover { color:#880000; }
  div.page_nav { padding:8px; }
  div.page_nav a:visited { color:#0000cc; }
  div.page_path { padding:8px; border:solid #d9d8d1; border-width:0px 0px 1px}
  div.page_footer { padding:4px 8px; background-color: #d9d8d1; }
  div.page_footer_text { float:left; color:#555555; font-style:italic; }
  div.page_body { padding:8px; }
  div.title, a.title {
  	display:block; padding:6px 8px;
  	font-weight:bold; background-color:#edece6; text-decoration:none; color:#000000;
  }
  a.title:hover { background-color: #d9d8d1; }
  div.title_text { padding:6px 0px; border: solid #d9d8d1; border-width:0px 0px 1px; }
  div.log_body { padding:8px 8px 8px 150px; }
  .age { white-space:nowrap; }
  span.age { position:relative; float:left; width:142px; font-style:italic; }
  div.log_link {
  	padding:0px 8px;
  	font-size:10px; font-family:sans-serif; font-style:normal;
  	position:relative; float:left; width:136px;
  }
  div.list_head { padding:6px 8px 4px; border:solid #d9d8d1; border-width:1px 0px 0px; font-style:italic; }
  a.list { text-decoration:none; color:#000000; }
  a.list:hover { text-decoration:underline; color:#880000; }
  table { padding:8px 4px; }
  th { padding:2px 5px; font-size:12px; text-align:left; }
  tr.light:hover, .parity0:hover, pre.sourcelines.stripes > :nth-child(4n+1):hover { background-color:#edece6; }
  tr.dark, .parity1, pre.sourcelines.stripes > :nth-child(4n+3) { background-color:#f6f6f0; }
  tr.dark:hover, .parity1:hover, pre.sourcelines.stripes > :nth-child(4n+3):hover { background-color:#edece6; }
  td { padding:2px 5px; font-size:12px; vertical-align:top; }
  td.closed { background-color: #99f; }
  td.link { padding:2px 5px; font-family:sans-serif; font-size:10px; }
  td.indexlinks { white-space: nowrap; }
  td.indexlinks a {
    padding: 2px 5px; line-height: 10px;
    border: 1px solid;
    color: #ffffff; background-color: #7777bb;
    border-color: #aaaadd #333366 #333366 #aaaadd;
    font-weight: bold;  text-align: center; text-decoration: none;
    font-size: 10px;
  }
  td.indexlinks a:hover { background-color: #6666aa; }
  div.pre { font-family:monospace; font-size:12px; white-space:pre; }
  div.diff_info { font-family:monospace; color:#000099; background-color:#edece6; font-style:italic; }
  div.index_include { border:solid #d9d8d1; border-width:0px 0px 1px; padding:12px 8px; }
  div.search { margin:4px 8px; position:absolute; top:56px; right:12px }
  .linenr { color:#999999; text-decoration:none }
  div.rss_logo { float: right; white-space: nowrap; }
  div.rss_logo a {
  	padding:3px 6px; line-height:10px;
  	border:1px solid; border-color:#fcc7a5 #7d3302 #3e1a01 #ff954e;
  	color:#ffffff; background-color:#ff6600;
  	font-weight:bold; font-family:sans-serif; font-size:10px;
  	text-align:center; text-decoration:none;
  }
  div.rss_logo a:hover { background-color:#ee5500; }
  pre { margin: 0; }
  span.logtags span {
  	padding: 0px 4px;
  	font-size: 10px;
  	font-weight: normal;
  	border: 1px solid;
  	background-color: #ffaaff;
  	border-color: #ffccff #ff00ee #ff00ee #ffccff;
  }
  span.logtags span.tagtag {
  	background-color: #ffffaa;
  	border-color: #ffffcc #ffee00 #ffee00 #ffffcc;
  }
  span.logtags span.branchtag {
  	background-color: #aaffaa;
  	border-color: #ccffcc #00cc33 #00cc33 #ccffcc;
  }
  span.logtags span.inbranchtag {
  	background-color: #d5dde6;
  	border-color: #e3ecf4 #9398f4 #9398f4 #e3ecf4;
  }
  span.logtags span.bookmarktag {
  	background-color: #afdffa;
  	border-color: #ccecff #46ace6 #46ace6 #ccecff;
  }
  span.difflineplus { color:#008800; }
  span.difflineminus { color:#cc0000; }
  span.difflineat { color:#990099; }
  div.diffblocks { counter-reset: lineno; }
  div.diffblock { counter-increment: lineno; }
  pre.sourcelines { position: relative; counter-reset: lineno; }
  pre.sourcelines > span {
  	display: inline-block;
  	box-sizing: border-box;
  	width: 100%;
  	padding: 0 0 0 5em;
  	counter-increment: lineno;
  	vertical-align: top;
  }
  pre.sourcelines > span:before {
  	-moz-user-select: -moz-none;
  	-khtml-user-select: none;
  	-webkit-user-select: none;
  	-ms-user-select: none;
  	user-select: none;
  	display: inline-block;
  	margin-left: -5em;
  	width: 4em;
  	color: #999;
  	text-align: right;
  	content: counters(lineno,".");
  	float: left;
  }
  pre.sourcelines > a {
  	display: inline-block;
  	position: absolute;
  	left: 0px;
  	width: 4em;
  	height: 1em;
  }
  tr:target td,
  pre.sourcelines > span:target,
  pre.sourcelines.stripes > span:target {
  	background-color: #bfdfff;
  }
  
  /* Graph */
  div#wrapper {
  	position: relative;
  	margin: 0;
  	padding: 0;
  	margin-top: 3px;
  }
  
  canvas {
  	position: absolute;
  	z-index: 5;
  	top: -0.9em;
  	margin: 0;
  }
  
  ul#nodebgs {
  	list-style: none inside none;
  	padding: 0;
  	margin: 0;
  	top: -0.7em;
  }
  
  ul#graphnodes li, ul#nodebgs li {
  	height: 39px;
  }
  
  ul#graphnodes {
  	position: absolute;
  	z-index: 10;
  	top: -0.8em;
  	list-style: none inside none;
  	padding: 0;
  }
  
  ul#graphnodes li .info {
  	display: block;
  	font-size: 100%;
  	position: relative;
  	top: -3px;
  	font-style: italic;
  }
  
  /* Comparison */
  .legend {
      padding: 1.5% 0 1.5% 0;
  }
  
  .legendinfo {
      border: 1px solid #d9d8d1;
      font-size: 80%;
      text-align: center;
      padding: 0.5%;
  }
  
  .equal {
      background-color: #ffffff;
  }
  
  .delete {
      background-color: #faa;
      color: #333;
  }
  
  .insert {
      background-color: #ffa;
  }
  
  .replace {
      background-color: #e8e8e8;
  }
  
  .comparison {
      overflow-x: auto;
  }
  
  .header th {
      text-align: center;
  }
  
  .block {
      border-top: 1px solid #d9d8d1;
  }
  
  .scroll-loading {
    -webkit-animation: change_color 1s linear 0s infinite alternate;
    -moz-animation: change_color 1s linear 0s infinite alternate;
    -o-animation: change_color 1s linear 0s infinite alternate;
    animation: change_color 1s linear 0s infinite alternate;
  }
  
  @-webkit-keyframes change_color {
    from { background-color: #A0CEFF; } to {  }
  }
  @-moz-keyframes change_color {
    from { background-color: #A0CEFF; } to {  }
  }
  @-o-keyframes change_color {
    from { background-color: #A0CEFF; } to {  }
  }
  @keyframes change_color {
    from { background-color: #A0CEFF; } to {  }
  }
  
  .scroll-loading-error {
      background-color: #FFCCCC !important;
  }
  
  #doc {
      margin: 0 8px;
  }
  304 Not Modified
  

phase changes are refreshed (issue4061)

  $ echo bar >> foo
  $ hg ci -msecret --secret
  $ get-with-headers.py localhost:$HGPORT 'log?style=raw'
  200 Script output follows
  
  
  # HG changelog
  # Node ID 2ef0ac749a14e4f57a5a822464a0902c6f7f448f
  
  changeset:   2ef0ac749a14e4f57a5a822464a0902c6f7f448f
  revision:    0
  user:        test
  date:        Thu, 01 Jan 1970 00:00:00 +0000
  summary:     base
  branch:      default
  tag:         tip
  bookmark:    @
  bookmark:    a b c
  bookmark:    d/e/f
  
  
  $ hg phase --draft tip
  $ get-with-headers.py localhost:$HGPORT 'log?style=raw'
  200 Script output follows
  
  
  # HG changelog
  # Node ID a084749e708a9c4c0a5b652a2a446322ce290e04
  
  changeset:   a084749e708a9c4c0a5b652a2a446322ce290e04
  revision:    1
  user:        test
  date:        Thu, 01 Jan 1970 00:00:00 +0000
  summary:     secret
  branch:      default
  tag:         tip
  
  changeset:   2ef0ac749a14e4f57a5a822464a0902c6f7f448f
  revision:    0
  user:        test
  date:        Thu, 01 Jan 1970 00:00:00 +0000
  summary:     base
  bookmark:    @
  bookmark:    a b c
  bookmark:    d/e/f
  
  

access bookmarks

  $ get-with-headers.py localhost:$HGPORT 'rev/@?style=paper' | egrep '^200|changeset 0:'
  200 Script output follows
   changeset 0:<a href="/rev/2ef0ac749a14?style=paper">2ef0ac749a14</a>

  $ get-with-headers.py localhost:$HGPORT 'rev/%40?style=paper' | egrep '^200|changeset 0:'
  200 Script output follows
   changeset 0:<a href="/rev/2ef0ac749a14?style=paper">2ef0ac749a14</a>

  $ get-with-headers.py localhost:$HGPORT 'rev/a%20b%20c?style=paper' | egrep '^200|changeset 0:'
  200 Script output follows
   changeset 0:<a href="/rev/2ef0ac749a14?style=paper">2ef0ac749a14</a>

  $ get-with-headers.py localhost:$HGPORT 'rev/d%252Fe%252Ff?style=paper' | egrep '^200|changeset 0:'
  200 Script output follows
   changeset 0:<a href="/rev/2ef0ac749a14?style=paper">2ef0ac749a14</a>

no style can be loaded from directories other than the specified paths

  $ mkdir -p x/templates/fallback
  $ cat <<EOF > x/templates/fallback/map
  > default = 'shortlog'
  > shortlog = 'fall back to default\n'
  > mimetype = 'text/plain'
  > EOF
  $ cat <<EOF > x/map
  > default = 'shortlog'
  > shortlog = 'access to outside of templates directory\n'
  > mimetype = 'text/plain'
  > EOF

  $ killdaemons.py
  $ hg serve -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log \
  > --config web.style=fallback --config web.templates=x/templates
  $ cat hg.pid >> $DAEMON_PIDS

  $ get-with-headers.py localhost:$HGPORT "?style=`pwd`/x"
  200 Script output follows
  
  fall back to default

  $ get-with-headers.py localhost:$HGPORT '?style=..'
  200 Script output follows
  
  fall back to default

  $ get-with-headers.py localhost:$HGPORT '?style=./..'
  200 Script output follows
  
  fall back to default

  $ get-with-headers.py localhost:$HGPORT '?style=.../.../'
  200 Script output follows
  
  fall back to default

errors

  $ cat errors.log

Uncaught exceptions result in a logged error and canned HTTP response

  $ killdaemons.py
  $ hg --config extensions.hgweberror=$TESTDIR/hgweberror.py serve -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
  $ cat hg.pid >> $DAEMON_PIDS

  $ get-with-headers.py localhost:$HGPORT 'raiseerror' transfer-encoding content-type
  500 Internal Server Error
  transfer-encoding: chunked
  
  Internal Server Error (no-eol)
  [1]

  $ killdaemons.py
  $ head -1 errors.log
  .* Exception happened during processing request '/raiseerror': (re)

Uncaught exception after partial content sent

  $ hg --config extensions.hgweberror=$TESTDIR/hgweberror.py serve -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
  $ cat hg.pid >> $DAEMON_PIDS
  $ get-with-headers.py localhost:$HGPORT 'raiseerror?partialresponse=1' transfer-encoding content-type
  200 Script output follows
  transfer-encoding: chunked
  content-type: text/plain
  
  partial content
  Internal Server Error (no-eol)

  $ killdaemons.py
  $ cd ..